Heat exchanger and corrugated fin

Abstract

A heat exchanger includes tubes arranged in one direction, and a corrugated fin provided between the tubes. The corrugated fin includes joints joined to the tubes, and fin bodies that connect the joints which are located next to each other along the wave shape. The fin body includes a cut-raised portion that has a shape in which a part of the fin body is cut and raised for promotion of heat transfer. The cut-raised portion includes a cut-raised end on at least one end of the cut-raised portion in the one direction. The cut-raised end has recesses and projections on its surface that increase hydrophilicity of the surface of the cut-raised end.

What is claimed is: 
     
         1 . A heat exchanger that performs heat exchange between a first fluid and a second fluid, the heat exchanger comprising:
 tubes which are arranged in one direction and in which the first fluid flows; and   a corrugated fin provided between the tubes, curved to have a wave shape, and configured to promote heat exchange between the first fluid and the second fluid, the second fluid flowing between the tubes, wherein   the corrugated fin includes joints that are joined to the tubes, and fin bodies that are each between and connect the joints which are located next to each other along the wave shape,   the fin body includes a cut-raised portion that has a shape in which a part of the fin body is cut and raised for promotion of heat transfer,   the cut-raised portion includes a cut-raised body that guides the second fluid, and a cut-raised end that is provided on at least one end of the cut-raised portion in the one direction and has a plate shape extending from the cut-raised body,   the cut-raised end has recesses and projections that increase hydrophilicity of a surface of the cut-raised end on at least one side of the cut-raised end in a thickness direction of the cut-raised end, and   the recesses and projections of the cut-raised end are configured to promote drainage of water toward the joint or a surface of the tube.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein the cut-raised end is provided on each of opposite ends of the cut-raised portion in the one direction. 
     
     
         3 . The heat exchanger according to  claim 1 , wherein
 the fin body includes a pair of curved connections curved and connected to the joints at opposite ends of the fin body in the one direction, and   the pair of curved connections each includes recesses and projections that increase hydrophilicity of a surface of the curved connection on at least one side of the curved connection in a thickness direction of the curved connection.   
     
     
         4 . The heat exchanger according to  claim 3 , wherein
 the cut-raised end provided on at least one end of the cut-raised portion in the one direction includes one cut-raised end that is provided at an end of the cut-raised portion on one side of the cut-raised portion in the one direction,   the recesses and projections of the one cut-raised end includes a plurality of grooves, and the recesses and projections of one of the pair of curved connections closer to the one cut-raised end also includes a plurality of grooves, and   at least one of the plurality of grooves of the one cut-raised end is connected to at least one of the plurality of grooves of the one of the pair of curved connections.   
     
     
         5 . The heat exchanger according to  claim 1 , wherein
 the fin body includes a pair of curved connections curved and connected to the joints at opposite ends of the fin body in the one direction,   the fin body includes a cut-raised gap that is provided adjacent to the cut-raised portion by formation of the cut and raised shape of the cut-raised portion,   at least one of the pair of curved connections has a notch extending thereinto from the cut-raised gap, and   the notch extends outward of a width of the cut-raised portion in the one direction.   
     
     
         6 . The heat exchanger according to  claim 1 , wherein the joint includes recesses and projections provided on a surface of the joint facing away from the joined tube for increase in hydrophilicity of the surface of the joint. 
     
     
         7 . The heat exchanger according to  claim 1 , wherein
 the corrugated fin includes tube side ridges that each includes the joint and a portion adjacent to the joint,   the tube side ridge is curved to have a convex surface joined to the tube,   the tube side ridge includes a plurality of hydrophilic grooves on the convex surface and a concave surface on the backside of the convex surface for increase in hydrophilicity of the convex and concave surfaces of the tube side ridge, and   the plurality of hydrophilic grooves on the convex surface has a groove depth smaller than a groove depth of the plurality of hydrophilic grooves on the concave surface.   
     
     
         8 . The heat exchanger according to  claim 1 , wherein
 the corrugated fin includes tube side ridges that each includes the joint and a portion adjacent to the joint,   the tube side ridge is curved to have a convex surface joined to the tube,   the tube side ridge includes a plurality of hydrophilic grooves on the convex surface and a concave surface on a backside of the convex surface for increase in hydrophilicity of the convex and concave surfaces of the tube side ridge, and   the plurality of hydrophilic grooves on the convex surface has a groove width wider than a groove width of the plurality of hydrophilic grooves on the concave surface.   
     
     
         9 . The heat exchanger according to  claim 1 , wherein the cut-raised body includes recesses and projections that increase hydrophilicity of a surface of the cut-raised body on at least one side in a thickness direction of the cut-raised body. 
     
     
         10 . The heat exchanger according to  claim 1 , wherein
 the second fluid flows between the tubes in one cross direction crossing the one direction from one side as an upstream side to another side as a downstream side,   the fin body includes a flat surface along the one cross direction,   the flat surface includes a plurality of longitudinal grooves that increase hydrophilicity of the flat surface, and   the plurality of longitudinal grooves extends in the one direction.   
     
     
         11 . The heat exchanger according to  claim 10 , wherein
 the flat surface includes a plurality of lateral grooves that increase hydrophilicity of the flat surface, and   the plurality of lateral grooves crosses the plurality of longitudinal grooves and extends in the one cross direction.   
     
     
         12 . The heat exchanger according to  claim 1 , wherein
 the second fluid flows between the tubes in one cross direction crossing the one direction from one side as an upstream side to another side as a downstream side,   the fin body includes a flat surface along the one cross direction,   the flat surface includes a plurality of lateral grooves that increase hydrophilicity of the flat surface, and   the plurality of lateral grooves extends in the one cross direction.   
     
     
         13 . The heat exchanger according to  claim 1 , wherein the second fluid is a gas that generates condensed water by heat exchange with the first fluid. 
     
     
         14 . The heat exchanger according to  claim 1 , being provided in an environment to be exposed to water. 
     
     
         15 . The heat exchanger according to  claim 1 , wherein the tubes extend in a vertical direction. 
     
     
         16 . The heat exchanger according to  claim 1 , wherein a depth of a recess included in the recesses and projections is  10  pm or deeper. 
     
     
         17 . The heat exchanger according to  claim 11 , wherein a depth of a groove included in the plurality of longitudinal grooves is 10 μm or deeper, and a depth of a groove included in the plurality of lateral grooves is 10 μm or deeper. 
     
     
         18 . The heat exchanger according to  claim 1 , wherein the recesses and projections of the cut-raised end are provided on each of opposite sides of the cut-raised end in the thickness direction. 
     
     
         19 . The heat exchanger according to  claim 1 , wherein the cut-raised portion for promoting heat transfer is a louver. 
     
     
         20 . A corrugated fin for a heat exchanger performing heat exchange between a first fluid and a second fluid, the corrugated fin being disposed between tubes arranged in one direction, being curved to form a wave shape, and promoting the heat exchange between the first fluid flowing through the tubes and the second fluid flowing between the tubes,
 the corrugated fin comprising:   joints joined to the tubes; and   fin bodies that are each between and connect the joints which are located next to each other along the wave shape, wherein   the fin body includes a cut-raised portion that has a shape in which a part of the fin body is cut and raised for promotion of heat transfer,   the cut-raised portion includes a cut-raised body that guides the second fluid, and a cut-raised end that is provided on at least one end of the cut-raised portion in the one direction and has a plate shape extending from the cut-raised body,   the cut-raised end has recesses and projections that increase hydrophilicity of a surface of the cut-raised end on at least one side of the cut-raised end in a thickness direction of the cut-raised end, and   the recesses and projections of the cut-raised end are configured to promote drainage of water toward the joint or a surface of the tube.